A comparative evaluation of the CF:CS and CRS models in Pb-210 chronological studies applied to hydrographic basins in Brazil

The Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess Pb-210 models have been applied to a Pb-210 data set providing of eighteen sediments profiles sampled at four riverine systems occurring in Brazil, South America: Corumbatai River basin (S1=Site 1, Sao Paulo State), Atibaia River basin (S2=Site 2, Sao Paulo State), Ribeirao dos Bagres basin (S3=Site 3, Sao Paulo State) and Amazon River mouth. (S4=Site 4, Amapa State). These sites were chosen for a comparative evaluation of the performance of the CF:CS and CRS models due to their pronounced differences on the geographical location, geological context, soil composition, biodiversity, climate, rainfall, and water flow regime, among other variable aspects. However, all sediments cores exhibited a common denominator consisting on a database built from the use of the same techniques for acquiring the sediments major chemical composition (SiO2, Al2O3, Na2O, K2O, CaO, MgO, Fe2O3, MnO, P2O5, TiO2 and LOI-Loss on Ignition) and unsupported/excess 210Pb activity data. In terms of sedimentation rates, the performance of the CRS model was better than that of the CF:CS model as it yielded values more compatible with those expected from field evidences. Under the chronological point of view, the CRS model always provided ages within the permitted range of the Pb-210-method in the studied sites, whereas the CF:CS model predicted some values above 150 years. The SiO2 content decreased in accordance with the LOI increase in all cores analyzed and such inverse relationship was also tracked in the SiO2-LOI curves of historical trends. The SiO2-LOI concentration fluctuations in sites S1 and S3 also coincided with some Cu and Cr inputs in the drainage systems. (C) 2014 Elsevier Ltd. All rights reserved.

Spatial patterns of species richness and phylogenetic diversity of woody plants in the neotropical savannas of Brazil

Savanna woody plant communities are widespread in Brazil, where this vegetation type can be divided into core-central and marginal areas within its range of distribution. The study of diversity patterns of plant communities can provide insights into the distribution, biogeography, and diversity of plant species in widespread biomes. The objectives of this study were to measure standard and phylogenetic indices of diversity in woody plant communities of the savanna vegetation of Brazil (Cerrado) throughout its extensive range. Based on a metaanalysis, the diversity indexes were compared using traditional statistical methods, a phylogenetic approach, and by mapping. Similar patterns were found for phylogenetic and traditional indexes of diversity in core and marginal areas, suggesting that both lower and higher diversity sites can occur within the Cerrado geographical area. The only difference was found in low diversity, disjunct savanna sites within the Amazon basin, which are isolated by the Amazon River from the more continuous central-southern Cerrado area.

Empobrecimento e podzolização de solos lateríticos da bacia do Rio Negro e gênese dos podzóis na alta Bacia da Amazônia

Pós-graduação em Geografia - IGCE

Mercury Redox Chemistry in the Negro River Basin, Amazon: The Role of Organic Matter and Solar Light

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Major Aspects of the Mercury Cycle in the Negro River Basin, Amazon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Seasonality on the Interaction of Mercury with Aquatic Humic Substances Extracted from the Middle Negro River Basin (Amazon)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seasonal behavior of mercury species in waters and sediments from the Negro River Basin, Amazon, Brazil

Total (HgT), reactive (HgR) and organic (Hg ORG) mercury species have been quantified in non-filtered waters collected from the Negro River Basin, Amazon (from January/2002 through January/2004), in both black and white water bodies. Black waters presented the highest HgT, HgORG and HgR concentration (29.1 ng L-1, 1.63 ng L-1 and 3.9 ng L-1, respectively), while, white waters presented the lowest HgT, Hg ORG and HgR concentration (8.8 ng L-1, 0.49 ng L-1 and 1.2 ng L-1, respectively). An inverse correlation between HgT and the water level over the basin was obtained, although the HgORG concentration has increased in the first rainy months and then decreased as the water level rose. Total mercury in surface sediments (0-10 cm) ranged from 70 to 271 mg kg-1 being the methylmercury 0.47-1.79 % of this stock. The results indicate that HgR and the labile dissolved organic matter were introduced into the aquatic environment during the flooding season, especially in the earlier stages, thus contributing to mercury methylation. ©2007 Sociedade Brasileira de Química.

The influence of seasonalness on the structural characteristics of aquatic humic substances extracted from Negro River (Amazon state) waters: Interactions with Hg(II)

In this work, humic substances were extracted from water samples collected monthly from the Negro River basin in the Amazon state (Brazil) to study their properties in the Amazonian environment and interactions with the mercury ion considering the influence of seasonalness in this formation. The C/H, C/N and C/O atomic ratio parameters, functional groups, concentration of semiquinone-type free radicals, pH, pluviometric and fluviometric indices, and mercury concentrations were interpreted using hierarchical cluster analysis (HCA) and principal component analysis (PCA). The statistical analyses showed that when the pluviometric index was greater and the fluviometric index was smaller, the degree of humification of aquatic substances was greater. The following decreasing order of the degree of humification of the AHS collected monthly was established: Nov/02 to Feb/03 > Mar/02 to May/02 > Jun/02 to Oct/02. The greatest concentrations of mercury were detected in more humidified samples. These results suggest that due to inter and/or intra-molecular rearrangements, the degree of humification of aquatic humic substances is related to its affinity for Hg(II) ions. ©2007 Sociedade Brasileira de Química.

Apistogramma ortegai (Teleostei: Cichlidae), a new species of cichlid fish from the Ampyiacu River in the Peruvian Amazon basin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of the flooding gradient on tree community diversity in varzea forests of the purus river, central Amazon, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

An ethnobotanical study of anti-malarial plants among indigenous people on the upper Negro River in the Brazilian Amazon

In this article we present the plants used for the treatment of malaria and associated symptoms in Santa Isabel do Rio Negro in the Brazilian Amazon. The region has important biological and cultural diversities including more than twenty indigenous ethnic groups and a strong history in traditional medicine. The aims of this study are to survey information in the Baniwa, Baré, Desana, Piratapuia, Tariana, Tukano, Tuyuca, Yanomami ethnic communities and among caboclos (mixed-ethnicity) on: a) plant species used for the treatment of malaria and associated symptoms; b) dosage forms and c) distribution of these anti-malarial plants in the Amazon. Information was obtained through classical ethnobotanical and ethnopharmacological methods from interviews with 146 informants in Santa Isabel municipality on the upper Negro River, Brazil. Fifty-five mainly native neotropical plant species from 34 families were in use. The detailed uses of these plants were documented. The result was 187 records (64.4%) of plants for the specific treatment of malaria, 51 records (17.5%) of plants used in the treatment of liver problems and 28 records (9.6%) of plants used in the control of fevers associated with malaria. Other uses described were blood fortification ('dar sangue'), headache and prophylaxis. Most of the therapeutic preparations were decoctions and infusions based on stem bark, root bark and leaves. These were administered by mouth. In some cases, remedies were prepared with up to three different plant species. Also, plants were used together with other ingredients such as insects, mammals, gunpowder and milk. This is the first study on the anti-malarial plants from this region of the Amazon. Aspidosperma spp. and Ampelozizyphus amazonicus Ducke were the most cited species in the communities surveyed. These species have experimental proof supporting their anti-malarial efficacy. The dosage of the therapeutic preparations depends on the kind of plant, quantity of plant material available, the patient's age (children and adults) and the local expert. The treatment time varies from a single dose to up to several weeks. Most anti-malarial plants are domesticated or grow spontaneously. They are grown in home gardens, open areas near the communities, clearings and secondary forests, and wild species grow in areas of seasonally flooded wetlands and terra firme (solid ground) forest, in some cases in locations that are hard to access. Traditional knowledge of plants was found to be falling into disuse presumably as a consequence of the local official health services that treat malaria in the communities using commercial drugs. Despite this, some species are used in the prevention of this disease and also in the recovery after using conventional anti-malarial drugs.

Maturation and growth curves of Macrobrachium Carcinus (Linnaeus) (Crustacea, Decapoda, Palaemonidae) from Ribeira de Iguape River, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Association of acepromazine with propofol in giant amazon turtles Podocnemis expansa reared in captivity

PURPOSE: To evaluate the effects of different concentrations of an anesthetic association in giant amazon turtles (Podocnemis expansa).METHODS: Twenty healthy P. expansa of both sexes weighing between 1.0 and 1.5kg commercially bred in the Araguaia River Valley, Goias, Brazil, were separated into two groups (G1 n=10 and G2 n=10). Each group received a respective protocol: P1=acepromazine (0.5 mg/kg IM) and propofol (5 mg/kg IV) and P2=acepromazine (0.5 mg/kg IM) and propofol (10 mg/kg IV). The acepromazine was administered in the left thoracic member and the propofol in the cervical vertebral sinus. Assessments were made of the anesthetic parameters of locomotion, muscle relaxation, response to pain stimuli in the right thoracic and pelvic members and heartbeat.RESULTS: The anesthetic induction time was the same for both protocols (P1 and P2); however the P2 effects were of a longer duration.CONCLUSION: The sedation achieved with both protocols (P1 and P2) were satisfactory for the biological sample collection, physical examinations and minor surgeries on this species.